Steam-engine



(ModeL) 2 Sheets'Sheet 1. J. CURTIS; Steam Engine.

No. 230,245. Patented July .20, 1880.

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m A W N-PETERS, H1010 u RAPHER, WASHINGTON. D O.

PATENT OFFICE.

JOHN CURTIS, OF NORTH DORSET, VERMONT.

STEAM-ENGINE.

SPECIFICATION forrning part of Letters Patent No. 230,245, dated July20, 1880,-

Application filed April 3, 1880. (Model.)

To all whom it may concern:

Be it known that I, J OHN CURTIS, of North Dorset, in the county ofBennington, and in, the State of Vermont, have invented certain new anduseful Improvements in Steam-Eirgines; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, and to the letters of referencemarked thereon, making a part of this specification.

The nature of my invention consists in the construction and arrangementof a rotary steam-engine of the class in which the steamcylinderrotates, as will be hereinafter more fully set forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the annexed drawings, in which-4 Figure 1 is a plan view of my improved rotary steam-engine. Fig. 2 isa vertical section through the steam-chest and the cylinder surroundingthe rotating shaft. Fig. 3 is a section of the steam-cylinder and itsshaft. Fig. 4 shows the stop or piece L.

A represents the frame-work of the engine, constructed in any suitablemanner, and pro vided with suitable bearings a a and b b, for the twoshafts B and C to rotate in, said shafts being not in the same but onparallel lines and their inner ends a suitable distance apart, as shown.On the inner end of the shaft 0 is secured the fly-wheel E, and on theinner end of the shaft B is secured the steam-cylinderD.

F is the piston in the cylinder D, secured on a piston-rod, d, whichpasses through stuffingboxes in both ends of the cylinder, and one endof said rod has an eye, which is placed on a wrist-pin, e, in the sideof the fly-wheel.

The cylinder D is provided with the usual steam-passages h h, leadingfrom opposite ends toward the center, and communicating with twocorresponding passages, i 13, in the shaft B. These passages i runlongitudinally in said shaft beyond the first bearing a, and then openon opposite sides in the surface of the shaft. Surrounding this portionof the cylinder-shaft B is a stationary casing, G, communicating throughtwo ports, m m, with the stationary steam-chest H, within which is thevalve I for reversing the engine. This valve I is provided with asuitable rod and handle for movin g the same, so that the steam can passfrom the steam-chest through either of the ports m, while theexhaust-steam will pass through the other port into the hollow n in thevalve, through the side port, 19, and out at I from the steam-chest. Thelive steam enters the chest at 1 Between the two ports m m, within theeasing G, is an abutment, 8, extending from the inner periphery of thecasing to the shaft B, as shown in Fig. 2. Directly opposite thisabutment is another abutment, 8, extending from the shaft B to a certainpoint distant from the inner periphery of the casing. Between theabntments and the casing is placed a curved bar or segment, J, havingcogs upon its outer edge, and provided at each end with a projection, t,which fits between the shaft and the casing, as shown. This segment ismovable by means of a pinion, w, on a shaft, 4;.

1n engines of this class the cylinder is gen erally hung upon trunnions;but instead of doing this I hang the cylinder on the shaft B, the sameas the fly-wheel; and instead of ad mitting and exhausting the steam ina line with the axis of the shaft, Iextend the ports or passages 11 inthe shaft and bring them to the surface beyond the bearing, and thesteam is admitted and exhausted at this point, uotin a line with theaxis of the shaft, but at its surface and at right angles to its axis.

By this arrangement I prevent any action of the steam in the linealdirection of the shaft, and thus obviatethe necessity of havinga hollowfiy-wheel shaft with a stationary bar tosupport a trunnion upon the sideof the cylinder nearest to the fly-wheel. In short I obviate thenecessity of having any support or arrangement whatever upon that sideof the cylinder to prevent it from being forced or driven nearer to thefly-wheel. Thus I am enabled to place the cylinder much nearer theflywheel, and at the same time greatly simplify the construction andcorrespondingly diminish the expense of building the machine.

The steam is admitted and exhausted,as before stated, through the ports2, entering the shaft at right angles to its axis, the steam be ing heldto the shaft on the one side in the semicircular space 41 in the casing,the other half of the circular space being used for the exhaust. Thereare no valves to be operated, but the steam-ports pass around from thesteam-space into the exhaust-space, and from that into the steam-spaceagain, one port always being in the exhaust-space when the other is inthe steamspace. The ports are therefore not steam-ports only, butsteam-ports and exhaust-space, according as they are in the steam-spaceor the exhaust-space.

The cogged segment J forms a cut-o1fby which to shorten or lengthen thespace occupied by the steam through which the steamports pass. In thisadjustable cutting-oft apparatus are valves 00 ac, which will 1)\ eventthe steam from passing in one direction, but offer no special resistanceto its passing freely in the other direction.

It will be understood that there are to be stutfing-boxcs at each end ofthe cylinder, where the piston-rod passes in and out, and around thecylinder-shaft each side of the apparatus, through which the steam isadmitted to and exhausted from the cylinder, as well as around thevalve-stem at the top of the steamchest.

This engiue may also be used for other purposes. By removing thecut-otIJand the pinion operating the same and inserting the piece L, (shown inFig. 4,) to till up the space occupied by said pinion and up to theabutment s, the machine, with the passages enlarged, becomes a perfecthydraulic engine to be operated with water under pressure. It would alsobecome, by applying power to propel it, a most perfect double-actinghydraulic or pneumatic pump, combining within itself all thecapabilities of both a suction and force pump, and all without the useof any valve.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination of the steam-chest H, with valve I, casing G,' withports on m, abutments 8, and the shaft B, with ports 13 i, opening onthe surface thereof at right angles to its axis, substantially as andfor the purposes herein set forth.

2. The eogged segmental cut-oft J, operated by means of a shaft andpinion, in combination with casing G, having abutmeuts s 8,substantially as and for the purposes herein set forth.

3. In a rotar' engine, the combination of the shaft B, having passages71, cylinder D, with passages h, shaft 0, fly-wheel E, steam-chest H,with valve I, casing G, having ports at m and abut-meats s, and thecut-off J, operated by the pinion 10, all constructed and arrangedsubstantially as and for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand andseal this 11th day of March, 1880.

JOHN CURTIS. [L. s.] Witnesses:

AUSTIN Lam), JOHN W. COOK.

